Inorganic supports bond formation

The enantioselective C—C and C—X bond-formation catalyzed by inorganic supported heterogeneous chiral catalysts is summarized in Table 2.3, and selected examples are further described in this section. 

Table 2.3 Examples of heterogeneous asymmetric carbon-carbon and carbon-heteroatom bond formation using inorganic supports. 

The application of transition metal oxide monolayer/support systems as carriers for platinum allows the possibility of modification of the properties of platinum in a wide range [5]. According to our previous works we adopted an optimal loading of platinum (2 %w). The reaction of platinum compound with OH groups of the support proceeded to the formation of transition metal-O-Pt bond, according to the reaction (3) - a useful tool for obtaining well dispersed noble metal on the surface of inorganic support [6,7]. 

During the last decade a variety of mctluxloiogies have been developed to immobili/e molecular homogeneous catalysts on the surface of heterogeneous organic as well as inorganic polymeric materials (a) adsorption of the catalyst into the pores of the support, (b) encapsulation of the catalyst within the confines of cavities of the support, the Sii-callcd ship in the bottle technique", (c) attachment of the catalyst to the support by covalent bond formation and (d) direct synthesis into the final composite material [7. ... 

Arylyne cyclization is an important reaction affording the formation of carbocycles in the synthesis of complex molecules. CT-Bonded metal salt polymer or organic moiety linked to the inorganic support, silaphenylmercuiic triflate, showed efficient catalytic activity for a variety of mercury(ll) trifluoromethanesulfonate [Hg(OTf)J-catalyzed reactions [104,132-134]. Examples described by Equations (8.36)-(8.43) present cyclo- and cycloisometization reactions leading to the synthesis of both carbocycles and heterocycles. 

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